论文部分内容阅读
本文通过对在新疆南部塔里木盆地北缘博斯腾湖采集的一根953cm的岩心进行了早全新世以来的古气候重建。对BSTC2000岩心进行了碳酸盐矿物组成、Ca/1000Sr,有机质TOC,C/N和C/S分析,并结合BSTC2000岩心附近的一个沉积物剖面的孢粉资料,利用多指标重建了8500aBP以来的古气候变化特征。在2个平行岩心中对保存的植物叶片、草籽,以及全有机质进行了9个AMS14C年代测定。8500～8100aBP气候冷湿,钻孔位置为河流-滨湖相环境,沉积物中有3层泥炭层。从8100～6400aBP,气温升高,湖泊扩张,气候暖湿,湖泊可能为最高湖面时期。而从6400～5100aBP湖泊稍微下降,气候变冷。在中全新世晚期从5100～3100aBP气候变得高温干旱,但其间的4400～3800aBP有短暂的气候变冷,早期大量的冰雪融水补给博斯腾湖,使得湖泊水位上升。湖泊的第二个高湖面期是5200～3800aBP。在3100～2200aBP气候冷湿,由于蒸发减弱而湖泊有所扩张,湖泊在3100至2800aBP期间是最后一次短暂的高湖面期。这次短期高湖面后,湖泊由于较长时期的低温而引起的供水减少,湖泊收缩。从2200～1200aBP,气候变得干热,湖泊收缩。尽管从1200aBP以来,温度有所下降,气候变得暖干,湖泊又开始有所上升,但是没有达到博斯腾湖出水口孔雀河的海拔高度。
In this paper, a 953cm core collected from Bosten Lake in the northern margin of Tarim Basin in southern Xinjiang was used to reconstruct the paleoclimate since the Early Holocene. Carbonate mineral composition, Ca / 1000Sr, organic matter TOC, C / N and C / S analysis of BSTC2000 core were carried out. According to the pollen data of a sediment profile near BSTC2000 core, Paleoclimatic changes. Nine AMS14C dating of preserved plant leaves, grass seeds, and total organic matter were carried out in two parallel cores. 8500 ~ 8100aBP cold and wet climate, drilling location for the river - lake environment, the sediment has three peat layers. From 8100 to 6400 aBP, the temperature rises, the lake expands, the climate is warm and wet, and the lake may be the highest lake period. The lake dropped slightly from 6400 to 5100 aBP and the climate became colder. During the Late Mid-Holocene, the climate became hot and humid from 5100 to 3100 aBP. However, during the short period of 4400 to 3800 aBP, there was a short-term climate change. Early abundant snow and ice melt provided Bosten Lake, causing the lake water level to rise. The lake’s second high lake period is 5200 ~ 3800aBP. In 3100-2200aBP, the climate is cold and wet, with lakes expanding due to weakened evaporation. The lake was the last short high lake period from 3100 to 2800 a BP. After this short-term high lake, the lake reduced its supply due to the longer period of low temperature. From 2200 to 1200aBP, the climate becomes dry and hot, and the lakes shrink. Although the temperature dropped and the climate became warmer since 1200aBP, the lake started to rise again but did not reach the altitude of Peacock River at Bosten Lake outlet.